While camping on an island on the Columbia River with perfect visibility, four adults witnessed what I believe to be three objects, but possibly one, in a triangular shape. It appeared to be at a very high altitude and was extremely large or again, they were seperate objects. It travelled east to west. There was no sound. After 15 seconds or so, the leading light or tip of the triangle dimmed out and it was no longer visible. When the remaining two got to the same exact point in the sky where the first one disappeared, they did also.

((NUFORC Note: We suspect that the three objects were the U. S. Navy "NOSS" satellites. Satellites disappear from the sight of viewers on the ground when the former fly into the Earth's shadow, and therefore they no longer are illuminated by the Sun. PD))